restore screenshot

git-svn-id: https://plugins.svn.wordpress.org/chatmeim-mini-messenger/trunk@970514 b8457f37-d9ea-0310-8a92-e5e31aec5664
only screenshots in assets folder

git-svn-id: https://plugins.svn.wordpress.org/chatmeim-mini-messenger/trunk@970516 b8457f37-d9ea-0310-8a92-e5e31aec5664